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const std = @import("std");
pub const ParsedCommand = struct {
name: []const u8,
args: ?[]const u8,
output_redirect: ?[]const u8,
error_redirect: ?[]const u8,
};
pub fn parseCommand(input: []const u8) ParsedCommand {
var i: usize = 0;
var cmd_buf = std.ArrayList(u8){};
defer cmd_buf.deinit(std.heap.page_allocator);
while (i < input.len and input[i] == ' ') : (i += 1) {}
if (i >= input.len) {
return .{ .name = "", .args = null, .output_redirect = null, .error_redirect = null };
}
if (input[i] == '\'' or input[i] == '"') {
const quote = input[i];
i += 1;
while (i < input.len and input[i] != quote) : (i += 1) {
_ = cmd_buf.append(std.heap.page_allocator, input[i]) catch {};
}
if (i < input.len) i += 1;
} else {
while (i < input.len and input[i] != ' ') : (i += 1) {
if (input[i] == '\\' and i + 1 < input.len) {
i += 1;
_ = cmd_buf.append(std.heap.page_allocator, input[i]) catch {};
} else {
_ = cmd_buf.append(std.heap.page_allocator, input[i]) catch {};
}
}
}
while (i < input.len and input[i] == ' ') : (i += 1) {}
var redirect_pos: ?usize = null;
var error_redirect_pos: ?usize = null;
var j = i;
while (j < input.len) : (j += 1) {
if (j + 1 < input.len and input[j] == '2' and input[j + 1] == '>') {
error_redirect_pos = j;
j += 1;
} else if (input[j] == '1' and j + 1 < input.len and input[j + 1] == '>') {
redirect_pos = j;
j += 1;
} else if (input[j] == '>') {
redirect_pos = j;
}
}
const cmd_name = cmd_buf.toOwnedSlice(std.heap.page_allocator) catch "";
var args: ?[]const u8 = null;
var output_redirect: ?[]const u8 = null;
var error_redirect: ?[]const u8 = null;
var args_end = input.len;
if (redirect_pos) |pos| {
if (pos < args_end) args_end = pos;
}
if (error_redirect_pos) |pos| {
if (pos < args_end) args_end = pos;
}
while (args_end > i and input[args_end - 1] == ' ') : (args_end -= 1) {}
if (args_end > i) {
args = input[i..args_end];
}
if (redirect_pos) |pos| {
var k = pos;
if (input[k] == '1') k += 1;
if (k < input.len and input[k] == '>') k += 1;
while (k < input.len and input[k] == ' ') : (k += 1) {}
if (k < input.len) {
var redir_buf = std.ArrayList(u8){};
defer redir_buf.deinit(std.heap.page_allocator);
while (k < input.len and input[k] != ' ' and !(k + 1 < input.len and input[k] == '2' and input[k + 1] == '>')) : (k += 1) {
_ = redir_buf.append(std.heap.page_allocator, input[k]) catch {};
}
output_redirect = redir_buf.toOwnedSlice(std.heap.page_allocator) catch null;
}
}
if (error_redirect_pos) |pos| {
var k = pos + 2;
while (k < input.len and input[k] == ' ') : (k += 1) {}
if (k < input.len) {
var redir_buf = std.ArrayList(u8){};
defer redir_buf.deinit(std.heap.page_allocator);
while (k < input.len and input[k] != ' ') : (k += 1) {
_ = redir_buf.append(std.heap.page_allocator, input[k]) catch {};
}
error_redirect = redir_buf.toOwnedSlice(std.heap.page_allocator) catch null;
}
}
return .{ .name = cmd_name, .args = args, .output_redirect = output_redirect, .error_redirect = error_redirect };
}
pub fn parseArgs(allocator: std.mem.Allocator, cmd_name: []const u8, args_str: ?[]const u8) ![]const []const u8 {
var args_list = std.ArrayList([]const u8){};
try args_list.ensureTotalCapacity(allocator, 16);
errdefer args_list.deinit(allocator);
try args_list.append(allocator, cmd_name);
if (args_str) |args| {
var i: usize = 0;
var arg_buf = std.ArrayList(u8){};
defer arg_buf.deinit(allocator);
while (i < args.len) {
if (args[i] == '\'') {
i += 1;
while (i < args.len and args[i] != '\'') : (i += 1) {
try arg_buf.append(allocator, args[i]);
}
if (i < args.len) i += 1;
} else if (args[i] == '"') {
i += 1;
while (i < args.len and args[i] != '"') : (i += 1) {
if (args[i] == '\\' and i + 1 < args.len) {
const next = args[i + 1];
if (next == '"' or next == '\\') {
i += 1;
try arg_buf.append(allocator, args[i]);
} else {
try arg_buf.append(allocator, args[i]);
}
} else {
try arg_buf.append(allocator, args[i]);
}
}
if (i < args.len) i += 1;
} else if (args[i] == '\\' and i + 1 < args.len) {
i += 1;
try arg_buf.append(allocator, args[i]);
i += 1;
} else if (args[i] == ' ') {
if (arg_buf.items.len > 0) {
try args_list.append(allocator, try arg_buf.toOwnedSlice(allocator));
}
i += 1;
} else {
try arg_buf.append(allocator, args[i]);
i += 1;
}
}
if (arg_buf.items.len > 0) {
try args_list.append(allocator, try arg_buf.toOwnedSlice(allocator));
}
}
return args_list.toOwnedSlice(allocator);
}
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